Audio modification for adjustable playback rate

ABSTRACT

Features described herein relate to providing the capability to playback audiovisual content in a comprehensible manner at a rate adjustable by the viewer. For example, if a viewer wishes to watch a one hour news program, but the viewer only has thirty minutes to view the program, playback of the program at twice the rate, but in a comprehensible manner is provided. To provide the playback of the video at the adjustable rate, substitute audio is generated by adding or removing audio content without changing the playback rate of the audio. The video at the adjusted playback rate and the substitute audio at the normal playback rate may have the same duration and in some embodiments, may be presented synchronously.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/561,355 filed on Sep. 5, 2019, which is a continuation of U.S.application Ser. No. 15/293,560, filed Oct. 14, 2016, now U.S. Pat. No.10,446,187, which is a continuation of U.S. application Ser. No.14/279,903, filed May 16, 2014, now U.S. Pat. No. 9,496,000.

BACKGROUND

Trick play (or trick mode) features allow for operations such as forwardand reverse play at multiple rates. Such features may be provided byskipping or duplicating frames of a video, or by adjusting the playbackframe rate. For example, in fast-forward and fast-reverse at a 2× rate,a system may provide the appearance of playing the video at double rate(forwards or backwards) by skipping playback of every other frame (e.g.,the frames are displayed at the same rate, but only half the frames arepresented), or by presenting every frame at twice the playback rate.Similarly, slow-forward and slow-reverse at a ½ rate provides theappearance of playing the video at half rate by displaying every frametwice (e.g., the frames are displayed at the same rate, but twice theframes are presented), by generating new frames in between the originalframes, or by presenting every frame at half the playback rate. Forskip-forward and skip-reverse, the system simply skips display of aduration of the video timeline (i.e., skips a predetermined number offrames) before returning to normal playback.

These and other trick play features provide the viewer a searchcapability to advance or reverse the playback timeline of the content toa point where the viewer would like to begin or resume watching thecontent at a normal playback rate (e.g., skipping a commercial). Thetrick play features, however, substantially limit and may entirelyeliminate the viewer's ability to experience as intended (e.g.,comprehend) the content during use of these trick play features. Forone, the audio that is synchronized to the video may not have ananalogous capability to simply skip (or duplicate) a slice of the audiocorresponding to the skipped or duplicated frames. Were this to occur,the audio would become incomprehensible. For this reason, playback ofthe audio is often suspended during trick play.

To provide a viewer a better experience, there remains a need to be ableto present audiovisual content at an adjustable rate desired by theviewer, but in a manner that remains comprehensible.

SUMMARY

The following summary is for illustrative purposes only, and is notintended to limit or constrain the detailed description.

Features herein relate to providing the capability to playbackaudio/visual content in a comprehensible manner at a rate adjustable bythe viewer and/or provider. For example, if a viewer wishes to watch aone hour news program, but the viewer only has thirty minutes to viewthe program, playback of the program at twice the rate, but in acomprehensible manner is provided in accordance with one aspect. Asanother aspect, a capability is provided for the content provider topresent a commercial or other item in an abbreviated manner if a viewerwishes to skip the commercial.

To provide the playback at the adjustable rate, some features relate togenerating substitute audio for replacing the original audio or alteringthe original audio in the audiovisual content. When the playback rate ofthe video in the audiovisual content is adjusted above or below thenormal playback rate of the audiovisual content, the substitute audio iscontemporaneously presented at the normal playback rate of theaudiovisual content. The video at the adjusted/modified playback rateand the substitute audio at the normal playback rate may have the sameduration and in some embodiments, may be presented synchronously.

To generate substitute audio in one aspect, audio content is added orremoved without changing the playback rate. As such, the audio is stillcomprehensible, but the duration is adjusted to that of the video at theadjusted playback rate. Different algorithms may be applied to alter theoriginal audio or generate the substitute audio depending, for example,on the magnitude of the playback rate adjustment and/or based on thecomplexity of video and or original audio.

The summary here is not an exhaustive listing of the novel featuresdescribed herein, and are not limiting of the claims. These and otherfeatures are described in greater detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood with regard to the followingdescription, claims, and drawings. The present disclosure is illustratedby way of example, and not limited by, the accompanying figures in whichlike numerals indicate similar elements.

FIG. 1 illustrates prior art audio-visual content at various playbackrates.

FIGS. 2A and 2B illustrate modified audio-visual content at variousplayback rates according to one or more embodiments.

FIGS. 3 and 4 illustrate a flow diagram according to one or moreembodiments.

FIG. 5 illustrates an example communication network on which one or moreembodiments may be implemented.

FIG. 6 illustrates hardware elements of various computing devicesaccording to one or more embodiments.

DETAILED DESCRIPTION

In the following description of various illustrative embodiments,reference is made to the accompanying drawings, which form a parthereof, and in which is shown, by way of illustration, variousembodiments in which aspects of the disclosure may be practiced. It isto be understood that other embodiments may be utilized, and structuraland functional modifications may be made, without departing from thescope of the present disclosure.

Audiovisual content may include an output rate and a playback rate.Output rate may refer, for example, to a rate at which data/frames (notnecessarily all of the frames) of a video or audio aredisplayed/presented, streamed, or output to a device. Examples of outputrate include a rate at which a device displays frames of a video orpresents audio, a rate at which a server streams video frames or audiodata to a device, a rate at which a memory buffer outputs video framesor audio data, etc.

Playback rate, on the other hand, may refer to a rate at which contentwithin the video frames or audio are displayed/presented, streamed, oroutput to a device. The distinction between output rate and playbackrate is described with respect to FIG. 1, which illustrates variousexamples of prior art audiovisual content that include videosynchronized with audio.

As shown in audiovisual content 101.1, 101.2, and 101.3 of FIG. 1, thevideo is made up of a sequence of video portions 102.1 through 102.6(e.g., video frames) that are output (e.g. presented, displayed,streamed, etc.) in sequence at a predetermined output rate (e.g., aframe rate of 30 frames per second). If all of the video portions of theaudiovisual content are output in a forward sequence as in 101.1, theplayback rate (e.g., the rate at which the content in the video ispresented) is the same as the output rate (e.g., the rate at which theframes are presented). If, however, every other video portion of theaudiovisual content are output in a forward sequence as in 101.2, andthe frames are presented at the same predetermined output rate as in101.1, the content in the video frames will appear at twice the outputrate, and thus the video in 101.2 will have a playback rate that istwice the output rate.

Audiovisual content 101.1 may include video having a normal playbackrate, such that the content of the video frames are presented, forexample, at the same rate at which the live-action in the video isrecorded on the frames, or in which the video is otherwise intended tobe displayed under normal viewing conditions (e.g. a rate at which acartoon video is designed to be viewed).

A duration or playback time of the video, or portion thereof, is equalto the output rate multiplied by the number of video portions that areplayed back. For example, the playback time of the entire audiovisualcontent 101.1, including six video frames at a normal output rate of 30frames per second, would be ⅕ of a second.

Audiovisual content may include audio that is synchronized to the video.For example audiovisual content 101.1, includes audio made up of sixaudio portions 103.1 through 103.6. While displayed as discreteportions, the audio may include a continuous sequence of datarepresenting audio of the same duration as the entire video (e.g. 102.1through 102.6). The audio is displayed in FIG. 1 as discrete portions(or durations) to show that each duration is synchronized to one of thevideo portions.

As described above, audiovisual content may be played back at ratesother than the normal playback rate. For example, a video-on-demandsystem, digital video recorder, set top box, or other computing devicemay include trick play or trick mode features such as forward andreverse play at multiple rates (e.g., 2×, 4×, ½×, ¼×, −2×, −4×, −½×,−¼×) and forward and reverse skip play (e.g., jump 30 seconds forward orbackwards in time) at multiple durations. In prior analog systems (e.g.VHS) the audiovisual content could be played back faster or slowersimply by running the medium (e.g. videocassette) faster or sloweracross the pickup head of the player, thereby changing the output rateof the frames and playback rate of the content faster or slower. Indigital content, however, trick play is can be accomplished by a numberof methods. For example, as discussed above, a client (e.g., a set topbox), may skip frames of a video (e.g., fetch ever other frame of avideo stream) and output those frames at the same output rate as in thenormal playback rate situation. For example, to double the playback rate(e.g. 2×) as in audiovisual content 101.2, every other video portion(e.g., 102.1, 102.3, and 102.5) are played back in sequence at the sameoutput rate as in audiovisual content 101.1. This results in the contentof the video appearing to be played back at double the rate, when inactuality; only half the content is presented.

Several other examples of trick play including a modified playback rateinclude a client fetching and presenting only intra-coded frames (e.g.,MPEG-4 I-frames) to play back at a fast-forward or fast reverse playbackrate, a client fetching and presenting all frames of a video at a fasteror slower output rate resulting faster or slower playback rates, aserver delivering an alternate video having a normal frame output ratebut with the content (e.g., imagery) in the frames recorded or encodedin the frames at twice the playback rate (e.g., a 2× stream), a serverflooding a client decoder at twice/half the output rate, etc.

Adjusting the playback rate in these manners, e.g., by skipping orduplicating video portions, present problems for playing back the audiothat is intended to be synchronized with the video, because the audioportions cannot likewise be skipped, or duplicated, or appropriatelymodified at the playback rate and still maintain comprehensibility.Instead, they must be compressed or expanded in time. That is, all ofthe portions of the audio are output, but the output rate of the audiorate is adjusted. For example in audiovisual content 101.2 (e.g., a 2×fast-forward playback), every other video portion is played, but allaudio portions are played, so each audio portion must be compressed intime to half its original duration, so that the total duration the audiois the same as a reduced number of video portions presented in the 2×play. This would result in playing back the audio portions 103.1 and103.2 at twice the speed, and in a distorted, high-pitch.

Under such conditions, while having a common playback rate, the videoand audio have different output rates (e.g., the video at the normaloutput rate and the audio at the modified output rate). The result maybe a loss of audio synchronization (e.g., lip synchronization) to thevideo. Further, the faster the audiovisual content is played back themore incomprehensible the audio becomes. For example, as the audio iscompressed in time, the pitch of the audio increases respectively, andwords can blend to the point that variations in tone and inflection andoverall enunciation of the words are not discernible. For this reason,many playback systems do not output the audio when the audiovisualcontent is played back at a rate other than the normal playback rate. Toaddress these problems, various embodiments presented below replace theaudio portions with substitute audio during playback of audiovisualcontent at playback rates other than the normal playback rate.

FIGS. 2A and 2B illustrate various embodiments of audiovisual contentincluding substitute audio in place of the original audio portions(e.g., 103.1 through 103.6). In each of these examples the output rateof the video is the same as in FIG. 1 (e.g., the normal output rate),with the playback rate adjusted by reducing or increasing the number ofvideo portions of the audiovisual content that are presented. Unlike theaudio in FIG. 1, however, the substitute audio in FIGS. 2A and 2B havethe same playback rate as that of the video (e.g., the normal playbackrate). In various examples, the substitute audio is generated from theoriginal audio in the audiovisual content, but with some of the contentremoved or additional content added to account for the reduction oraddition in playback time at the off-normal rates.

For example, if the video portion 102.1-102.6 contains a video scene oftwo actors having a conversation, the substitute audio may contain analternative audio recording of two actors having an abbreviated (orextended) conversation. As further described below, the actors in theabbreviated audio may skip unnecessary words, shorten pauses betweenwords, and may speak alternative dialogue so that the meaning of theconversation is preserved but the conversation takes half the time.Similarly, an extended version of the audio may have the actors speakingtheir normal lines of dialogue, but with longer pauses between spokenwords or sentences, or the actors may speak extra lines of dialogue, sothat the same conversation takes twice as long.

Audiovisual content 201.1 in FIG. 2A illustrates one embodiment with thevideo at the 2× playback rate and substitute audio at the 1× playbackrate. The result is audiovisual content with video that appears to bepresented twice as fast but with audio that may be synchronized to thevideo that sounds as if it is presented in a comprehensible normalfashion. In audiovisual content 201.1 original audio portions 103.1through 103.6 are replaced with substitute audio 203.1 through 203.3.Substitute audio 203.1 may be presented contemporaneously with videoportion 102.1, substitute audio 203.2 may be presented contemporaneouslywith video portion 102.3, and substitute audio 203.3 may be presentedcontemporaneously with video portion 102.5.

Audiovisual content 201.2 in FIG. 2A illustrates another embodiment witha video at a ½× playback rate with substitute audio at the 1× playbackrate. In this embodiment, original audio portions 103.1 through 103.6are replaced with substitute audio portions 204.1 through 204.12, whichare respectively presented contemporaneously with the 12 video portions(e.g., video portions 102.1 through 102.6 each presented twice).

Audiovisual content 201.3 in FIG. 2B illustrates another embodiment withthe video at a negative 1× (e.g., 1× speed rewind) playback rate withthe substitute audio at a 1× playback rate. In this embodiment the videoportions are presented in reverse order sequence, while the substituteaudio is presented in a forward order. Original audio portions 103.6through 103.1 (each individually presented in the backwards direction aswell as in backwards order) are replaced with substitute audio 205.1through 205.6 (each presented in the forwards direction in forwardorder), respectively. As one example, the audio portion 205.1 may be thesame as 103.6 played at a forward 1× rate, 205.2 may be the same as103.5 played at a forward 1× rate, etc. In another example, 103.1-103.6may include a sequence of spoken sentences, which are partitioned at theboundary of each sentence, and sequence of the sentence rearranged inreverse order, but still played in the forward direction to create205.1-205.6. Audiovisual content 201.4 in FIG. 2B illustrates anotherembodiment with the video having a thirty second video skip rate (e.g.,played back at the normal playback rate with 30 seconds of the videoskipped) with substitute audio 206 at a 1× playback rate replacing theoriginal audio portions 103.3 through 103.902 that were previouslysynchronized to the skipped video portions. In audiovisual content201.4, having for example a 30 frames per second output rate, videoportion 102.903 is presented subsequent to video portion 102.2, skippingvideo portions 102.3 through 102.902 (e.g. 900 frames representing 30seconds of video).

During a playback duration that is shorter (e.g., 5 seconds) than theduration of the skipped content (e.g., 30 seconds), substitute audio 206may be inserted at a 1× playback rate. During this inserted shorterduration, no video may be played back, a previous video portion (e.g.,102.2) may be repeatedly played back, a substitute video portion 207(e.g., a still image, alternate video sequence) may be played back, or acombination of these may be used. The substitute audio 206, may includea spoken summary of the skipped portion, audio synchronized to asubstitute video portion, or any other audio having a length within theshortened duration. In some variations to audiovisual content 201.4,during the shortened duration of the skipped video, a user may select toreturn to the original video and audio at the original (e.g., normal)playback rate or a different modified playback rate. In response theselection, presentation or outputting of the audio visual content mayreturn to the beginning of the skipped portion (e.g., video portion102.3 and audio portion 103.3), to an audio and video portion prior tothe skipped portions (e.g., video portion 102.1 and audio portion103.1), or to some intermediate portion within the skipped audio videoportion (e.g., video portion 102.500 and audio portion 103.500). Forexample, if the skipped portion was an advertisement for a particularautomobile brand, and the substitute video portion 207 or substituteaudio portion 206 presented a summary or brief indication of the contentof the advertisement, a user may be prompted to view the advertisementin response to the substitute video or audio. In such a circumstance,the user could request to view the advertisement in its entirety (or aportion thereof) at the normal playback, or at a different playback rateaccording one of the other embodiments (e.g., a 2× playback rate).

Other embodiments may include a combination of the substitute audiopresented in audiovisual content 201.1, 201.2, 201.3, and 201.4. Forexample, audiovisual content at a negative 2× rate may includesubstitute audio created according to a combination of the methods ofcreating substitute audio 203.1 through 203.3 and substitute audio 205.1through 205.6. As another example, audiovisual content at a negative 30seconds skip video rate may include substitute audio that is createdaccording to methods for creating substitute audio 205.1 through 205.6and substitute audio 206.

In addition to the substitute audio being played back at a 1× playbackrate as discussed above with respect to 201.1, 201.2, 201.3, and 201.4,in other embodiments, the substitute audio may include audio at more orless than a 1× playback rate. For example, as further discussed below,audiovisual content 201.1 may include video at a 2× playback rate andaudio at a 1.2× playback rate, and audio visual content 201.2 mayinclude video at a ½× playback rate and audio at a 0.8× playback rate.

FIG. 3 illustrates a flow diagram of a process 300 according to one ormore embodiments for presenting audiovisual content at anadjusted/modified playback rate with substitute audio replacing (ormodifying) the original audio of the audiovisual content. The processmay optionally start in step 301 in which a computing device receives arequest for audio visual content. In various examples, the request maybe a user (e.g., viewer) request to present audiovisual content or maybe an automated request from the computing device to a remote device forretrieving the audiovisual content. The computing device, in variousexamples, maybe a presentation device such as a television, a personalcomputer, a tablet, a smart phone, a set top terminal, a kiosk, digitalvideo recorder or any other computing device capable of displaying theaudiovisual content on a display or outputting the audiovisual contentto a device with a display. In various other examples, the computingdevice may be a server, such as a video-on-demand server, a cloud orserver-based digital video recorder, a streaming server, or any otherserver capable of transmitting (e.g., streaming) the audiovisual contentto one or more remote terminals/premises for display.

In step 302, in response to the request for the audiovisual content, thecomputing device outputs the audiovisual content for display at a normalplayback rate (e.g., as predetermined by the content creator and/orprovider). Step 302 may include retrieving the content from a remotestorage device, such as a remote database or streaming server.Outputting the audiovisual content may include, for example,transmitting the audiovisual content in an uncompressed format (e.g.,pixel data, component or composite video) to a display device withanalog audio to a stereo or speakers, as encoded audiovisual data (e.g.,MPEG 2 or MPEG 4) to an audiovisual decoder, transmitting theaudiovisual content over one or more networks (e.g., hybrid fibercoaxial network, a fiber-optic network, cellular network, satellitenetwork, Wi-Fi, etc.) as a data stream, displaying the audiovisualcontent on a display, or combinations thereof.

In step 303, which may be a starting point for the method, the computingdevice may receive a request to modify the playback rate of theaudiovisual content. If the computing device does not receive such arequest, the process returns to step 302 to continue outputting theaudiovisual content at the normal playback rate. If the computing placedoes receive such a request, the process proceeds to step 304, in whichthe computing device determines an attribute, such as a value of themodified playback rate. The value may be included in the request ormaybe one of a plurality of predetermined playback values or ratesstored or available in the computing device and referenced by therequest. Playback values may indicate playback of the audiovisualcontent in the forward direction (e.g., a positive playback value) ormay indicate playback of the audiovisual content in the reversedirection (e.g., a negative playback value). The playback values, forexample, may indicate: one of a plurality of playback rates that areslower than the normal playback rate (e.g., playback value that are lessthan one, such as ¼× or ½×), one of a plurality of playback rates thatare faster than the normal playback rate (e.g., playback values that aregreater than one, such as 2×, 3×, 4×, 8×), the normal playback rate(e.g., a playback value equal to one), or a skip playback rateindicating a number of frames or a duration of the audiovisual contentto skip (e.g., 900 frames, 30 seconds, etc.).

After the attribute, e.g., value, of the modified playback rate isdetermined, substitute audio is selected in step 305 to replace ormodify the original audio portions associated with the video portionsaffected by the modified playback rate as, for example, in FIGS. 2A and2B. The substitute audio may be selected from (or existing audio may bemodified to be similar to) a plurality of substitute audios based uponthe value of the modified playback rate. For example, a modifiedplayback rate value of positive two, indicating a 2× playback rate maylead to a selection of substitute audio that is half the duration of theoriginal audio portions being replaced (e.g., audiovisual content201.1). As another example, a 2× playback rate may least to a selectionof substitute audio that is sixty percent of the duration of theoriginal audio but played back at a 1.2× rate to produce a final halfduration audio. As another example, a modified playback rate value ofpositive 30 seconds, indicating a skip forward of 30 seconds, may selectsubstitute audio of a shorter duration (e.g., 1 second, 5 second, etc.)that provides a brief summary of the audiovisual content that is beingskipped. For example, if the skipped portion is a commercialadvertisement skipped during a regular transmission, the substituteaudio may include a shorter-duration, audio-only advertisement relatedto the product presented in the full audiovisual commercialadvertisement.

The substitute audio may be selected not only based on the type ofmodified playback rate (e.g., fast forward, fast reverse, skip forward,skip reverse), but also based on the magnitude of the value (e.g.,magnitude) of the modified playback rate. For example a longer skippedduration may result in the selection of a respectively longer substituteaudio, or a faster playback rate may result in the selection ofrespectively shorter substitute audio that includes less information.Different algorithms of generating different types of substitute audioare further discussed below with respect to FIG. 4.

After the selection of the substitute audio in step 305, output of theaudiovisual content is switched in step 306 to outputting subsequentvideo portions at the modified playback rate with the selectedsubstitute audio at the normal playback rate. In various examples thesubstitute audio is output contemporaneously with the video portion towhich it is associated. This may include synchronization of eachsubstitute audio portion with its associated video portion. For examplea video portion that presents a speaker may be synchronized (e.g., lipsynchronized) with the associated substitute audio portion. Thesubstitute audio portions may be generated such that they present thesame or similar information as the original audio portions that theyreplace but in a shorter or longer duration as determined by themodified playback rate. In various examples, the substitute audio is notmerely the original audio output at a faster or slower rate, but isaudio that can be played back rate at the normal rate, but with more orless information. This may include, for example, removing pauses indialogue, replacing spoken words with longer or shorter synonymouswords, removing one or more play tracks of the original audio, replacingaudio content with a summary of the audio content, or othermodifications as further discussed with respect to FIG. 4. Variousembodiments may include video and audio timestamps from the originalvideo and audio at the normal playback rate maintained (e.g., at regularincrements of playback time) with the video at the modified playbackrate and with the substitute audio, so that synchronization (e.g., lipsync) may be periodically corrected.

In step 307, the computing device may determine if the modified playbackrate is to end. The determination could be based on the modifiedplayback rate being only for a predetermined limited duration (e.g., theend of the skip rate, a momentary fast-forward for a fixed duration,etc.) or may be based on receiving a request for a new playback rate. Ifstep 307 determines that the modified playback rate should continue (the“no” branch), the process returns to step 306 to output the video at themodified playback rate with the substitute audio at the normal playbackrate. If the determination is made that the modified playback rateshould end (e.g., a request for a new playback rate is received, a skipcompleted, etc.) (the “yes” branch), then it is determined in step 308whether the next playback rate as a normal playback rate or anothermodified playback rate. If the next playback rate is a normal playbackrate, such as when a skip is completed or when a normal playback rate isrequested, the process returns to step 302 in which the audiovisualcontent is played back at the normal playback rate with the originalaudio. If the next playback rate is another modified playback rate, theprocess returns to step 304 where the value of the new modified playbackrate is determined. The next playback rate in step 308 may result from anew request for a modified playback rate or may, for example, bepreprogramed to follow the previously requested playback rate. Forexample, if the present rate is 4×, but the previous rate was 2×, step308 may return playback to the previous 2× rate in step 304, rather thanthe 1× rate in step 302. The process continues until a request isreceived to stop playback altogether or the output of the end of theaudiovisual content is reached.

In various examples, the requests for different playback rates in steps303 and 308, and the determination in step 307 whether to end thecurrent playback rate may be based autonomously on and be performed inresponse to the complexity of the audiovisual content being played back.For example, as content is being played back (at whatever playback rateis currently selected), changes in the complexity of the content may bedetermined in step 307, and if the complexity of the content changes,the playback rate may be modified in step 308. For example, if thecomplexity of the content increases, the playback rate may be decreased(e.g., from 4× to 2×, 8× to 3×, etc.) to make the content morecomprehensible to the viewer, and if the complexity of the contentdecreases, the playback rate may be increased (e.g., from 2× to 4×, 1.2×to 3×, etc.), because the content is comprehensible at the increasedplayback rate.

In various additional examples, the playback rate of the video is notadjusted based on a changing complexity, but the selection of thesubstitute audio in step 305 is based on the complexity of theaudiovisual content. As such, the substitute audio may be selected (asdiscussed with respect to FIG. 4) based on both a playback rate of thevideo that is selected, the complexity of the video, the complexity ofthe original audio, or combinations thereof.

Complexity of the audiovisual content may be determined in various ways,including measuring the amount of motion or change of video content(e.g., imagery) from video frame to video frame, measuring the amount ofaudio variation in the original audio, counting the number of words,syllables, or inflections in speech in the audio (e.g., as reflected inclosed caption), etc.

As previously discussed there may be a plurality of different substituteaudios for the same video portion depending upon the modified playbackrate. FIG. 4 illustrates example process 400 for generating varioussubstitute audios for a particular associated video portion. The processbegins in step 401 when an attribute, e.g., a value related to themodified playback rate of a particular video portion is received forwhich the substitute audio is to be generated. In step 402, a differencein duration between the playback time of the video portion at themodified playback rate and the playback time of the video portion at thenormal playback rate is determined. The difference in duration may bemeasured in time (e.g., fractions of a second), in the terms of a ratioor percentage of the normal playback time (e.g., 0.5, ¼, 110%), in thenumber of frames, in fractions of frames, etc.

In step 403, a complexity of the video portion and/or the original audioportion to be replaced is analyzed. This may include analyzing thesubject matter depicted in the video portion. Based on the difference induration determined in step 402 and a complexity of the video portionand/or original audio portion determined in step 403, the substituteaudio portion is generated using one or more techniques of steps 404through 412. For example, if the video portion does not include anydialogue of speakers, modification to the audio that affects dialoguemay be skipped. In another example, if the video portion includesdialogue from a narrator only that is not depicted in the video portion,modification that does not concern synchronization may be chosen (e.g.,step 412 described below.) In a further example, as the modifiedplayback rate increases, certain aspects described below may become lesseffective earlier for content that is more complex and that includesmore information. The complexity of the audiovisual portion may bedetermined as discussed above with respect to FIG. 3.

In step 404, the original audio portion playback rate maybe increased ordecreased in proportion to the playback rate of the video. As discussedabove, such an increase or decrease in audio playback rate will resultin a respective increase or decrease in the pitch of the audio. Toaccount for the pitch shift, the accelerated or decelerated audio can bepitch shifted down or up, respectively, so that the accelerated ordecelerated audio is adjusted back to the pitch of the original audio.Step 404 may be used as a first step or partial step (or may be skipped)in adjusting the audio to correspond to the modified video. For example,if the video is played back at a 2× rate, step 404 may adjust the audioto a 1.2× rate, so that the remainder of 400 (e.g., 404-413) need onlyaccount a 1.67× adjustment (e.g., 1.2××1.67×=2×). As another example, ifthe video is played back at a 0.5× rate, step 404 may adjust the audioto a 0.8× rate, so that the remainder of 400 (e.g., 404-413) need onlyaccount for a 0.63× adjustment (e.g., 0.8××0.63×=0.5×).

In step 405, for example, the original audio portion may be changed togenerate the substitute audio by removing or adding one or more spokenwords. For example, in a dialogue spoken in the original audio portion,words that do not convey substantive information or convey lessimportant information (e.g., “the,” “a,” etc.) relative to theunderstanding of the dialogue may be deleted to shorten the duration ofthe substitute audio. Likewise, filler words adding little substantiveinformation or adding additional information about the associated videoportion can be added to lengthen the duration of the substitute audio.

In step 406, the original audio portion may be changed to generate thesubstitute audio by replacing one or more spoken words with one or morealternative spoken words or sounds conveying the same or similarinformation. For example, to shorten the duration of the substituteaudio one or more longer words can be replaced with one or moresynonymous shorter words, and to lengthen the duration of the substituteaudio one or more shorter words can be replaced with one or moresynonymous longer words. For each spoken word, a library database ofaudio with substitute words may be maintained and searched during theprocess of replacing the words. The library may be generated, forexample, by each original speaker recording the substitute wordsseparate from the original audio. Alternatively or additionally, thelibrary may be generated autonomously based on a thesaurus database ofsynonymous words, and artificial synthesis of the articulated synonymousword such that the pitch, inflections, and other manners in which thespeaker enunciates words is matched according to a voice profile of thespeaker. The profile may be based on analysis of the speaker's voice inthe video or based on analysis of the speaker's voice from a separaterecording.

In another aspect of step 406, the speaker may similarly recorddifferent substitute audios replacing the original audio portions,respectively, for different playback rates. For example, one or morespeakers may record different dialogues conveying the same or similarinformation as the original audio portion but in different durations asdetermined by the modified playback rate.

In step 407, the original audio portion may be changed to generate thesubstitute audio by removing or changing durations of pauses in dialogueor other silent intervals within the original audio portion. Forexample, intervals between spoken words from a speaker can be shortenedsuch that the overall length of the dialogue is shortened while thedistinction between each word is sufficiently maintained. Similarly,intervals between spoken words from one or more speakers can belengthened to increase the overall length of the dialogue.

In step 408, the original audio portion may be changed to generate thesubstitute audio by removing or changing in duration one or moreintervals having an audio amplitude below or above a threshold value.For example, intervals of an audio portion in which no dialogue occurs,but is filled with background noise (e.g., wind blowing), may be removedor reduced in duration based on the background noise being below athreshold value. Similarly, intervals of an audio portion in which nodialogue occurs but is filled with loud background noise (e.g., awaterfall, crowds cheering, etc.), may be lengthened or duplicated basedon the background noise being above a threshold value to extend thelength of substitute audio.

In step 409, the original audio portion may be changed to generate thesubstitute audio by removing or adding or attenuating or amplifying abackground sound. Step 409 differs from step 408 in that the backgroundsound is not lengthened or shortened, but instead, its amplitude isaltered so that other aspects of the audio portion that have beenchanged (e.g., dialogue changed, pauses added or removed, etc.) areaugmented by the altered background sound. For example, backgroundsounds may be reduced so dialogue that has been shortened is clearer andmore easily discernible to the listener. As another example, backgroundsounds may be added to fill in pauses in dialogue or other silentportions that have been lengthened.

In step 410, the original audio portion may be changed to generate thesubstitute audio by removing, attenuating, or amplifying one or moreother sounds. For example if multiple persons are speaking in the videoportion, the dialogue from all but one of the persons may be attenuatedor removed so that the one remaining dialogue is clearer and more easilydiscernible to the listener. In step 411, the original audio portion maycomprise a plurality of audio tracks, and one or more of the pluralityof audio tracks may be removed, attenuated, or amplified. For example,each source of audio within an audio portion (e.g., multiple speakers,background waterfall noise, each member of an orchestra, etc.) may berecorded on a separate audio track. To make a particular one of theaudio tracks more clear and discernible, other ones of the plurality ofaudio tracks may be attenuated or removed altogether. Alternatively oradditionally, the particular one of the audio tracks may be amplifiedabove the remaining ones of the plurality of audio tracks to make theamplified track more clear and discernible. Similar to step 409, steps410 and 411 may be used to improve the clarity of other aspects of theaudio portion that have been changed in duration.

In step 412, the substitute audio may be generated by replacingintervals of the original audio portion with an entirely different audioportion, such as for example, a summary of the action in the video or asummary of the information conveyed in the original audio. For example,if the difference in duration determined in step 402 is sufficientlyshortened (by a skip play or high fast forward rate) and/or the videoportion or original audio portion is of significant complexity thatsteps 404 through 411 are not adequate enough to reduce the length thesubstitute audio while conveying sufficient information to make thevideo at the modified playback rate understandable, a brief summary maybe inserted that explains what is occurring in the video portion duringthe duration of the playback at the modified rate. Step 412 may include,for negative video playback rates, generating substitute audio at thenormal forward playback rate that explains the content of the videowhile the video progresses backwards.

In step 413, the substitute audio at the normal or modified playbackrate (e.g., 1×, 1.2×) generated according to the previous steps issynchronized to the associated video at the modified playback rate. Forexample, spoken words may be shifted to start earlier or later to alignwith the movement of a speaker's lips in the video closer to when thespeaker is enunciating the shifted word (e.g., lip synchronization). Inanother aspect, certain words may be compressed and other words expandedin duration so that the words are synchronized to the changed rate oflip movement of one or more speakers. In circumstances where thedialogue is expanded or compressed, the dialogue may be pitch shifted upor down, respectively, so that he expanded or compressed words arepresented at the same pitch as when the words are output at the normalplayback rate (as in step 404).

Shifting spoken words in step 413 may also be done to simply extend theamount of time available to play back of the audio content. For example,by starting the audio playback 500 ms early and ending the audioplayback 500 ms late, the audio is increased in duration, and thus canbe compressed less (e.g., 1.3×) than an increase in playback rate of thevideo (e.g., 1.5×) to fit within the same duration.

In other aspects of step 413, the video portion at the modified playbackrate may be altered to synchronize motion imaged in the video portionwith sounds in the associated substitute audio. For example, lipmovement of a speaker may be altered such that the video portion is lipsynchronized to modified dialogue in the substitute audio. Altering thevideo portion may include separately recording a scene in the videoportion with different movements such that the movements aresynchronized to the modified dialogue (e.g., filming a scene 10 timeswith actors saying shortened or elongated lines or speaking at differentspeeds). In other aspects, altering the video portion may includemodifying autonomously the original video portion (e.g., alter lipmovement of a live person or an animated character) using syntheticvideo manipulation techniques (e.g., MPEG-4 Face and Body Animation).

At the end of process 400, one or more substitute audios may be storedon the computing device or at a remote storage device for use in process300 of FIG. 3. Alternatively, the process 400 may be performed inreal-time to generate substitute audio when a request in process 300 isreceived for adjusting the playback rate.

As one example of generating substitute audio according to the process400, the original audio may be modified by first removing backgroundsounds so that, for example, dialogue of one or more speakers can beclearly distinguished. The dialogue with the background sounds removedcan then be compressed or expanded according to an increased ordecreased playback rate to fit within the changed duration of themodified video playback time. Changing the audio playback rate of thedialogue has the effect of changing the pitch of the audio. To accountfor the change in pitch, the audio at the modified playback rate may bepitch-shifted back to the pitch of the dialogue at the normal playbackrate.

In various examples, processes 300 and 400 may be used together so avideo portion with modified playback at sequentially increasing rates(e.g., 1.5×, 2×, 4×, 8×, 16×, etc.) are respectively associated withsubstitute audios having a sequentially increasing amount ofmodification. For example, at a 1.5× fast forward rate, the playbackrate of the audio may be slightly increased and optionally pitch shifted(e.g., 1.2× faster) as in step 404, and pauses in the dialogue may beremoved as in step 407 words in a dialogue may simply be removed as instep 404. As the playback rate increases to 2×, unnecessary words in thedialogue may be removed as in step 405 in addition or in place of steps404 and/or 407 and pauses in the dialogue may be shortened as in step406. As the playback rate further increases to 4×, steps 405, 406, 407,or combinations thereof may be performed in addition to substitution oflonger words with synonymous shorter words according to step 406, or byadditionally applying steps 408-411. As the playback rate furtherincreases to above 4×, the original audio may not maintainable in acomprehensible form when modified according to the techniques in process400, so instead, the original audio portion may be replaced with asummary is in step 412. As illustrated by this example, the order of thesteps in 400 need not be the order in which they are applied as video isincreased or decreased at incrementally faster or slower playbackspeeds.

FIG. 5 illustrates an example communication network 500 on which many ofthe various features described herein may be implemented. Network 500may be any type of information distribution network, such as satellite,telephone, cellular, wireless, etc. One example may be an optical fibernetwork, a coaxial cable network, or a hybrid fiber/coax distributionnetwork. Such networks 500 use a series of interconnected communicationlinks 501 (e.g., coaxial cables, optical fibers, wireless, etc.) toconnect multiple premises 502 (e.g., businesses, homes, consumerdwellings, etc.) to a distribution point such as local office or headend503. The local office 503 may transmit downstream information signalsincluding audiovisual content with original audio and one or moresubstitute audios at one or more playback rates onto the links 501, andeach premise 502 may have a receiver used to receive and process thosesignals including the audiovisual content.

There may be one link 501 originating from the local office 503, and itmay be split a number of times to distribute the signal to variouspremises 502 in the vicinity (which may be many miles) of the localoffice 503. The links 501 may include components not illustrated, suchas splitters, filters, amplifiers, etc. to distribute the signal.Portions of the links 501 may also be implemented with fiber-opticcable, while other portions may be implemented with coaxial cable, otherlines, or wireless communication paths.

The local office 503 may include an interface, such as a terminationsystem (TS) 504. More specifically, the interface 504 may be a cablemodem termination system (CMTS), which may be a computing deviceconfigured to manage communications between devices on the network oflinks 501 and backend devices such as servers 505-507 (to be discussedfurther below). The interface 504 may be as specified in a standard,such as the Data Over Cable Service Interface Specification (DOCSIS)standard, published by Cable Television Laboratories, Inc. (a.k.a.CableLabs), or it may be a similar or modified device instead. Theinterface 504 may be configured to place data on one or more downstreamfrequencies to be received by modems at the various premises 502, and toreceive upstream communications from those modems on one or moreupstream frequencies.

The local office 503 may also include one or more network interfaces508, which can permit the local office 503 to communicate with variousother external networks 509. These networks 509 may include, forexample, networks of Internet devices, telephone networks, cellulartelephone networks, fiber optic networks, local wireless networks (e.g.,WiMAx), satellite networks, and any other desired network, and thenetwork interface 508 may include the corresponding circuitry needed tocommunicate on the external networks 509, and to other devices on thenetwork such as a cellular telephone network and its corresponding cellphones.

As noted above, the local office 503 may include a variety of servers505-507 that may be configured to perform various functions. Forexample, the local office 503 may include a push notification server505. The push notification server 505 may generate push notifications todeliver data and/or commands to the various premises 502 in the network(or more specifically, to the devices in the premises 502 that areconfigured to detect such notifications). The local office 503 may alsoinclude a content server 506. The content server 506 may be one or morecomputing devices that are configured to provide audiovisual content tousers at their premises. This audiovisual content may be, for example,video on demand movies, television programs, video games, etc. Thecontent server 506 may include software to validate user identities andentitlements, to locate and retrieve requested audiovisual content, toencrypt the content, and to initiate delivery (e.g., streaming) of thecontent to the requesting user(s) and/or device(s).

The local office 503 may also include one or more application servers507. An application server 507 may be a computing device configured tooffer any desired service, and may run various languages and operatingsystems (e.g., servlets and JSP pages running on Tomcat/MySQL, OSx, BSD,Ubuntu, Redhat, HTML5, JavaScript, AJAx and COMET). For example, anapplication server may be responsible for generating the substituteaudio based on modified playback rates of audiovisual content. Yetanother application server may be responsible for formatting andinserting the substitute audio into the audiovisual content stream beingtransmitted to the premises 502. The application server may further beresponsible for forwarding the substitute audio to the premises 502separately from the audiovisual content for later insertion. Althoughshown separately, one of ordinary skill in the art will appreciate thatthe push server 505, content server 506, and application server 507 maybe combined. Further, here the push server 505, content server 506, andapplication server 507 are shown generally, and it will be understoodthat they may each contain memory storing computer executableinstructions to cause a processor to perform steps described hereinand/or memory for storing data (e.g., a library of substitute words).

An example premise 502 a, such as a home, may include an interface 520.The interface 520 can include any communication circuitry needed toallow a device to communicate on one or more links 501 with otherdevices in the network. For example, the interface 520 may include amodem 510, which may include transmitters and receivers used tocommunicate on the links 501 and with the local office 503. The modem510 may be, for example, a coaxial cable modem (for coaxial cable lines501), a fiber interface node (for fiber optic lines 501), twisted-pairtelephone modem, cellular telephone transceiver, satellite transceiver,local wi-fi router or access point, or any other desired modem device.Also, although only one modem is shown in FIG. 5, a plurality of modemsoperating in parallel may be implemented within the interface 520.Further, the interface 520 may include a gateway interface device 511.The modem 510 may be connected to, or be a part of, the gatewayinterface device 511. The gateway interface device 511 may be acomputing device that communicates with the modem(s) 510 to allow one ormore other devices in the premises 502 a, to communicate with the localoffice 503 and other devices beyond the local office 503. The gateway511 may be a set-top box (STB), digital video recorder (DVR), computerserver, personal computer or any other desired computing device. Thegateway 511 may also include (not shown) local network interfaces toprovide communication signals to requesting entities/computing devicesin the premises 502 a, such as display devices 512 (e.g., televisions),additional STBs or DVRs 513, personal computers 514, laptop computers515, wireless devices 516 (e.g., wireless routers, wireless laptops,notebooks, tablets and netbooks, cordless phones (e.g., Digital EnhancedCordless Telephone—DECT phones), mobile phones, mobile televisions,personal digital assistants (PDA), etc.), landline phones 517 (e.g.Voice over Internet Protocol—VoIP phones), and any other desireddevices. Examples of the local network interfaces include MultimediaOver Coax Alliance (MoCA) interfaces, Ethernet interfaces, universalserial bus (USB) interfaces, wireless interfaces (e.g., IEEE 802.11,IEEE 802.15), analog twisted pair interfaces, Bluetooth interfaces, andothers. Processes 300 and 400 may be performed any number of computingdevices (e.g., 505, 506, 507, 511-516, etc.) individually or incombination in the FIG. 1 architecture.

FIG. 6 illustrates general hardware elements that can be used toimplement any of the various computing devices discussed herein. Thecomputing device 600 may include one or more processors 601, which mayexecute instructions of a computer program to perform any of thefeatures described herein. The instructions may be stored in any type ofcomputer-readable medium or memory, to configure the operation of theprocessor 601. For example, instructions may be stored in a read-onlymemory (ROM) 602, random access memory (RAM) 603, removable media 604,such as a Universal Serial Bus (USB) drive, compact disk (CD) or digitalversatile disk (DVD), floppy disk drive, or any other desired storagemedium. Instructions may also be stored in an attached (or internal)hard drive 605. The computing device 600 may include one or more outputdevices, such as a display 606 (e.g., an external television, monitor,touchscreen), and may include one or more output device controllers 607,such as a video processor. There may also be one or more user inputdevices 608, such as a remote control, keyboard, mouse, touch screen,microphone, etc. The computing device 600 may also include one or morenetwork interfaces, such as a network input/output (I/O) circuit 609(e.g., a network card) to communicate with an external network 610. Thenetwork input/output circuit 609 may be a wired interface, wirelessinterface, or a combination of the two. In some embodiments, the networkinput/output circuit 609 may include a modem (e.g., a cable modem), andthe external network 610 may include the communication links 501discussed above, the external network 509, an in-home network, aprovider's wireless, coaxial, fiber, or hybrid fiber/coaxialdistribution system (e.g., a DOCSIS network), or any other desirednetwork. Additionally, the device may include a location-detectingdevice, such as a global positioning system (GPS) microprocessor 611,which can be configured to receive and process global positioningsignals and determine, with possible assistance from an external serverand antenna, a geographic position of the device.

The FIG. 6 example is a hardware configuration, although the illustratedcomponents may be implemented as software as well. Modifications may bemade to add, remove, combine, divide, etc. components of the computingdevice 600 as desired. Additionally, the components illustrated may beimplemented using basic computing devices and components, and the samecomponents (e.g., processor 601, ROM storage 602, display 606, etc.) maybe used to implement any of the other computing devices and componentsdescribed herein. For example, the various components herein may beimplemented using computing devices having components such as aprocessor executing computer-executable instructions stored on acomputer-readable medium, as illustrated in FIG. 6. Some or all of theentities described herein may be software based, and may co-exist in acommon physical platform (e.g., a requesting entity can be a separatesoftware process and program from a dependent entity, both of which maybe executed as software on a common computing device).

One or more aspects of the disclosure may be embodied in acomputer-usable data and/or computer-executable instructions, such as inone or more program modules, executed by one or more computers or otherdevices. Generally, program modules include routines, programs, objects,components, data structures, etc. that perform particular tasks orimplement particular abstract data types when executed by a processor ina computer or other data processing device. The computer executableinstructions may be stored on one or more computer readable media suchas a hard disk, optical disk, removable storage media, solid statememory, RAM, etc. As will be appreciated by one of skill in the art, thefunctionality of the program modules may be combined or distributed asdesired in various embodiments. In addition, the functionality may beembodied in whole or in part in firmware or hardware equivalents such asintegrated circuits, field programmable gate arrays (FPGA), and thelike. Particular data structures may be used to more effectivelyimplement one or more aspects of the disclosure, and such datastructures are contemplated within the scope of computer executableinstructions and computer-usable data described herein.

To provide a better user experience, it may be desirable for a systemsuch as a content delivery system or device such as a contentconsumption device to be able to identify which user(s) are in the roomand customize settings, profiles, or preferences to be specific to theuser(s) such as an active user or a group of identified users. Profiles,settings, or preferences may be customized based on the user who is incontrol of a remote control device or the group of users present in theviewing area or field of view of an image device. Determination of theuser in control of the remote control device may be ascertained fromanalysis of an image captured at the time of a signal transmission fromthe remote control device. A computing device may be used to process acaptured image and determine an associated user for the control signal.A user may be associated with the remote control device based onrelative positions of the user and the remote control device, and theuser in control of the remote control device may be identified as theactive user.

Although example embodiments are described above, the various featuresand steps may be combined, divided, omitted, rearranged, revised and/oraugmented in any desired manner, depending on the specific outcomeand/or application. Various alterations, modifications, and improvementswill readily occur to those skilled in art. Such alterations,modifications, and improvements as are made obvious by this disclosureare intended to be part of this description though not expressly statedherein, and are intended to be within the spirit and scope of thedisclosure. Accordingly, the foregoing description is by way of exampleonly, and not limiting. This patent is limited only as defined in thefollowing claims and equivalents thereto.

The invention claimed is:
 1. A system comprising: a first computingdevice and a second computing device; wherein the first computing devicecomprises: one or more first processors; and first memory storing firstinstructions that, when executed by the one or more first processors,cause the first computing device to: provide a video portion ofaudio-visual content at a modified playback rate different from a firstplayback rate of the video portion; determine, based on a duration ofthe video portion at the modified playback rate, an alternative audio tobe output at the first playback rate; and provide, with the videoportion at the modified playback rate, the alternative audio at thefirst playback rate; and wherein the second computing device comprises:one or more second processors; and second memory storing secondinstructions that, when executed by the one or more second processors,cause the second computing device to store the audio-visual content. 2.The system of claim 1, wherein the alternative audio comprises analtered version of an audio portion of the audio-visual content.
 3. Thesystem of claim 1, wherein the first instructions, when executed by theone or more first processors, further cause the first computing deviceto synchronize sounds of the alternative audio with action in the videoportion of the audio-visual content at the modified playback rate. 4.The system of claim 1, wherein the first instructions, when executed bythe one or more first processors, further cause the first computingdevice to determine the alternative audio to be output at the firstplayback rate by selecting, based on the duration of the video portionat the modified playback rate, the alternative audio from a plurality ofalternative audios, wherein a duration of the alternative audio at thefirst playback rate corresponds to the duration of the video portion atthe modified playback rate.
 5. The system of claim 1, wherein the firstinstructions, when executed by the one or more first processors, furthercause the first computing device to adjust a duration of the alternativeaudio at the first playback rate to the duration of the video portion atthe modified playback rate.
 6. The system of claim 1, wherein thealternative audio replaces an audio portion of the audio-visual content.7. The system of claim 1, wherein the first instructions, when executedby the one or more first processors, further cause the first computingdevice to modify sounds in the alternative audio at the first playbackrate to synchronize with lip movement of a person imaged in the videoportion.
 8. One or more non-transitory computer-readable media storinginstructions that, when executed, cause: providing a video portion ofaudio-visual content at a modified playback rate different from a firstplayback rate of the video portion; determining, based on a duration ofthe video portion at the modified playback rate, an alternative audio tobe output at the first playback rate; and providing, with the videoportion at the modified playback rate, the alternative audio at thefirst playback rate.
 9. The one or more non-transitory computer-readablemedia of claim 8, wherein the alternative audio comprises an alteredversion of an audio portion of the audio-visual content.
 10. The one ormore non-transitory computer-readable media of claim 8, wherein theinstructions, when executed, further cause synchronizing sounds of thealternative audio with action in the video portion of the audio-visualcontent at the modified playback rate.
 11. The one or morenon-transitory computer-readable media of claim 8, wherein theinstructions, when executed, cause the determining by causing selecting,based on the duration of the video portion at the modified playbackrate, the alternative audio from a plurality of alternative audios, andwherein a duration of the alternative audio at the first playback ratecorresponds to the duration of the video portion at the modifiedplayback rate.
 12. The one or more non-transitory computer-readablemedia of claim 8, wherein the instructions, when executed, further causeadjusting a duration of the alternative audio at the first playback rateto the duration of the video portion at the modified playback rate. 13.The one or more non-transitory computer-readable media of claim 8,wherein the alternative audio replaces an audio portion of theaudio-visual content.
 14. The one or more non-transitorycomputer-readable media of claim 8, wherein the instructions, whenexecuted, further cause modifying sounds in the alternative audio at thefirst playback rate to synchronize with lip movement of a person imagedin the video portion.
 15. A system comprising: a first computing deviceand a second computing device; wherein the first computing devicecomprises: one or more first processors; and first memory storing firstinstructions that, when executed by the one or more first processors,cause the first computing device to: determine a video portion, whereinthe video portion is to be output at a modified playback rate that isdifferent from a first playback rate of the video portion; modify, basedon the first playback rate and a duration of the video portion to beoutput at the modified playback rate, an audio portion corresponding tothe video portion; and cause output of the video portion at the modifiedplayback rate and output of the modified audio portion at the firstplayback rate; and wherein the second computing device comprises: one ormore second processors; and second memory storing second instructionsthat, when executed by the one or more second processors, cause thesecond computing device to store the video portion.
 16. The system ofclaim 15, wherein the first instructions, when executed by the one ormore first processors, further cause the first computing device tomodify the audio portion corresponding to the video portion by adding,to the audio portion and based on the modified playback rate of thevideo portion, information.
 17. The system of claim 15, wherein thefirst instructions, when executed by the one or more first processors,further cause the first computing device to modify the audio portioncorresponding to the video portion by removing, from the audio portionand based on the modified playback rate of the video portion,information.
 18. The system of claim 15, wherein the first instructions,when executed by the one or more first processors, further cause thefirst computing device to modify the audio portion corresponding to thevideo portion by: replacing, in the audio portion and based on themodified playback rate of the video portion, spoken words with longer orshorter synonymous words, or replacing audio content with a summary ofthe audio content in the audio portion.
 19. The system of claim 15,wherein a duration of the modified audio portion at the first playbackrate corresponds to the duration of the video portion at the modifiedplayback rate.
 20. The system of claim 15, wherein the firstinstructions, when executed by the one or more first processors, furthercause the first computing device to synchronize sounds of the modifiedaudio portion with the video portion.
 21. One or more non-transitorycomputer-readable media storing instructions that, when executed, cause:determining a video portion, wherein the video portion is to be outputat a modified playback rate that is different from a first playback rateof the video portion; modifying, based on the first playback rate and aduration of the video portion to be output at the modified playbackrate, an audio portion corresponding to the video portion; and causingoutput of the video portion at the modified playback rate and output ofthe modified audio portion at the first playback rate.
 22. The one ormore non-transitory computer-readable media of claim 21, wherein theinstructions, when executed, cause the modifying by causing adding, tothe audio portion and based on the modified playback rate of the videoportion, information.
 23. The one or more non-transitorycomputer-readable media of claim 21, wherein the instructions, whenexecuted, cause the modifying by causing removing, from the audioportion and based on the modified playback rate of the video portion,information.
 24. The one or more non-transitory computer-readable mediaof claim 21, wherein the instructions, when executed, cause themodifying by causing: replacing, in the audio portion and based on themodified playback rate of the video portion, spoken words with longer orshorter synonymous words, or replacing audio content with a summary ofthe audio content in the audio portion.
 25. The one or morenon-transitory computer-readable media of claim 21, wherein a durationof the modified audio portion at the first playback rate corresponds tothe duration of the video portion at the modified playback rate.
 26. Theone or more non-transitory computer-readable media of claim 21, whereinthe instructions, when executed, further cause synchronizing sounds ofthe modified audio portion with the video portion.